eendrickson



uitrit taire stmt @frn IMPROVEMENT IN THE CONSTRUCTION' OI SAIES.

TO ALL WHOM IT MAY CONOERN:

Be it known that I, E. M. II'ENDRICKSON, of Brooklyn, in the county of Kingmand State of New York, have invented a new and improved Iurglar-Proot' Safe and Vault; and'I do hereby declare that the following is a full, clear, and exact description thereof, which will enable those skilled in the art .to make and use the same, reference being had to the accompanying drawings, forming part ot' thisv spocitication, in which- Figure l is a side sectionalview of a portion of, the wall ot' a safe or vault constructed according to my invention. v

Figure 2, a plan or top view of the same.

Similar letters of reference indicate corresponding parts.

This invention relates to an improvement on that class of burglar-proot` safes and vaults in whichcliillcd cast-iron walls are employed in order to prevent an entrance being eiectcd by means of drilling. The chilled cast-iron walls nrc a great safeguard, as they can only be drilled by hard labor and a considerable expenditure of time; but as there are cases in which burglars can manage to operate repeatedly upon safes and vaults, the

latter, even when constructed with the cast-iron wa'lls, are not 'unfrequeutly broken into. The object of this invention is to render the cast-iron walls more secure than hitherto, and to this end it consists in having the walls cast around soft iron or other soft metal wire, bent in spiral form, and so closely or eompactlyarranged or disposed within the wall that a drill cannot avoid being brought incontact with it.A The softness of the wire otlers but little resistance to the great pressure under which the drill is required to operate, and hence, when the drill reaches the soft wire, the latter gives or yields, andthe drill will be delected from its course and broken, it not being able, under the pressure required to drill the chilled cast iron," (which is about twenty-live thousand pounds,)'to resist the strain brought upon it. It is well known to all artilicers in metal that it is extreincly ditlicult to drill through masses of metal not homogeneous throughout, as the drill, when itcomcs in contact with a soft mass, cuts or feeds itself too rapidly, and the only way to proceed in such eases is to graduaterthe i feed or pressure so that it will be commcnsuratewith the hardness' of the portion ot' metal being operated upon. But in my improvement, this cannot be effected, as the -drill will come in Contact with a soft Vmass at once, which immediately gives way, and causes the drill to be broken or destroyed.

In carrying-out myl invention, I have the soft metal, in the form of spiral wire springs A, arranged vertically and horizontally, so as to form a compact mass ofwire that the drill cannot avoid coming inl contact with; this inserted in the mould, and the iron B cast around it with a chill. The inner side of' the wall has a thin wrought-iron plate, C, secured to it by bolts or otherwise, in order to hold the cast-iron wall together incase of the latter being,lr broken by hammering. This, however, is an old feature, and is not so important in this connection, as the coiled wires A serve to keep the cast iron together in case of being broken, or is at present used with the chilled cast-iron walls. This improvement has been practically tested, and is an entiresucocss; it has been found impossible to drill through the wall, the drill vhaving been broken i'n every effort.

Having thus described my invention, what'I claim as new, and desire to secure by Letters Patent, ,.s-

I do not claim constructing the walls of safes by casting molten iron upon and around wrought-iron wires, rods, or bars, as this is not new; but what I do claim-as my improvement is, using,r for such puppose, and in the manner described, wires or rods, bent or coiled spirally, as herein shown and described.

i The above specification of my invention signed by me this 20th day of March, 1866.

` E. M. HENDRIOKSON.

Witnesses: l

M. M. LIVINGSTON, ALEX. F. Ronnnrs. 

